Biomedical subjects

F Qiu

Publications and source records attributed to F Qiu.

At least 19 recordsLinked to original sources

PubMed2006

The quantification of ADAMTS expression in an animal model of cerebral ischemia using real-time PCR.

BACKGROUND: ADAMTS1 and ADAMTS8 are proteases involved in extracellular matrix proteolysis and antiangiogenesis, but little is known about their expression and function in cerebral ischemia. We investigated the changes in ADAMTS1 and ADAMTS8 in a rat model of permanent middle cerebral artery occlusion (pMCAO). The expressions of glyseraldehyde-3-phosphate dehydrogenase (GAPDH), beta-actin, cyclophilin, and RPL13A were examined in order to validate the appropriate housekeeping genes for a long duration after inducing cerebral ischemia. METHODS: Male Sprague-Dawley rats were subjected to pMCAO, and ischemic penumbra was collected at 2, 24 h, 3, 7, and 21 days after inducing ischemia, ADAMTS1, ADAMTS8, and the four housekeeping genes were quantified using real-time polymerase chain reaction (PCR). RESULTS: The expression of beta-actin increased up to 21 days, and that of GAPDH decreased at 24 h after pMCAO, with no statistically significant changes in RPL13A and cyclophilin being detected. ADAMTS1 mRNA increased at 2 h after pMCAO, peaked at 24 h, and remained at a high level until 21 days. The expression of ADAMTS8 mRNA decreased at 2 and 24 h after pMCAO, followed by a slight increase at 3 days, and then decreased again at 7 days. CONCLUSION: The results suggest that RPL13A and cyclophilin are two appropriate housekeeping genes for the rat pMCAO model up to 21 days. ADAMTS1 mRNA levels increased, but ADAMTS8 decreased after pMCAO. Our data provide new insight into the mechanism of brain ischemia and self-repair after injury.

ADAM Proteins↗

PubMed2006

Self-assembled pattern formation of block copolymers on the surface of the sphere using self-consistent field theory.

The spherical surface is spatially discretized with triangular lattices to numerically calculate the Laplace-Beltrami operator contained in the self-consistent field theory (SCFT) equations using a finite volume method. Based on this method we have developed a spherical alternating-direction implicit (ADI) scheme for the first time to help extend real-space implementation of SCFT in 2D flat space to the surface of the sphere. By using this method, we simulate the equilibrium microphase separation morphology of block copolymers including AB diblocks, ABC linear triblocks and ABC star triblock copolymers occurred on the spherical surface. In general, two classes of microphase separation morphologies such as striped patterns for compositionally symmetric block copolymers and spotted patterns for asymmetric compositions have been found. In contrast to microphase separation morphology in 2D flat space, the geometrical characteristics of a sphere has a large influence on the self-assembled morphology. For striped patterns, several of spiral-form and ring-form patterns are found by changing the ratio of the radius of a sphere to the averaging width of the stripes. The specific pattern such as the striped and spotted pattern with intrinsic dislocations or defects stems from formed periodic patterns due to microphase separation of block copolymers arranged on the curved surface.

Adsorption↗

PubMed2005

Brn-3a is required for the generation of proprioceptors in the mesencephalic trigeminal tract nucleus.

The distribution of motor and proprioceptive neurons was investigated in the trigeminal nervous system of wild-type and Brn-3a knockout mice at embryonic day 18.5 and postnatal day 0. We found that the trigeminal motor nucleus (Mo5) contained abundant motoneurons in wild-type (mean number +/- SD per section = 128 +/- 22, range = 93-167) and knockout (mean number +/- SD per section = 121 +/- 23, range = 75-158) mice and that the cell size of Mo5 neurons was similar between these mice (wild-type, mean +/- SD = 165 +/- 59 microm2, range = 65-326 microm2; knockout, mean +/- SD = 167 +/- 59 microm2, range = 71-327 microm2). Mo5 neurons were immunoreactive for calcitonin gene-related peptide and such immunoreactive neurons were abundant in both wild-type and mutant mice. In the mesencephalic tract nucleus (Mes5) of wild-type mice, many proprioceptors (mean number +/- SD per section = 56 +/- 19, range = 27-85) that contained parvalbumin immunoreactivity were also observed. In knockout mice, however, Mes5 neurons could not be detected. The area of brainstems which normally contained the Mes5 was devoid of parvalbumin-immunoreactive proprioceptors. The present study suggests that Brn-3a is required for the development of proprioceptors but not motoneurons in the trigeminal nervous system.

Animals↗

PubMed2001

L-Altruronic acid formed by epimerization of D-galacturonic acid methyl esters during saponification of citrus pectin.

While searching for oligosaccharides containing rhamnose residues in the endopolygalacturonase (EPG) digest of saponified citrus pectin, we found several oligomers containing, in addition to galacturonic acid, a sugar previously unreported in pectin. The 1- and 2-D 1H NMR spectra of the oligosaccharides were consistent with the sugar being a uronic acid with its 2- and 3-hydroxyls being axial and 4-hydroxyl being equatorial. MALDI-TOF mass spectrometry indicated that the oligomers consisted solely of uronic acids. Reduction of the uronic acids in the oligosaccharides converted them to galactose and altrose. The altrose was found to be the L enantiomer by comparison of its trimethylsilyl (-)-2-butyl glycosides to those of authentic D-altrose and a racemic mixture. The sugar was not found in oligosaccharides prepared from EPG digestion of citrus pectin deesterified with pectin methylesterase rather than saponification. Thus, it appears that during saponification, a small proportion of the methylesterified galacturonic acid residues in pectins is epimerized at C-5 leading to formation of L-altruronic acid residues.

Carbohydrate Conformation↗

PubMed2001

NMR studies of molecular structure in fruit cuticle polyesters.

The cuticle of higher plants functions primarily as a protective barrier for the leaves and fruits, controlling microbial attack as well as the diffusion of water and chemicals from the outside environment. Its major chemical constituents are waxes (for waterproofing) and cutin (a structural support polymer). However, the insolubility of cutin has hampered investigations of its covalent structure and domain architecture, which are viewed as essential for the design of crop protection strategies and the development of improved synthetic waterproofing materials. Recently developed strategies designed to meet these investigative challenges include partial depolymerization using enzymatic or chemical reagents and spectroscopic examination of the intact polyesters in a solvent-swelled form. The soluble oligomers from degradative treatments of lime fruit cutin are composed primarily of the expected 10,16-dihydroxyhexadecanoic and 16-hydroxy-10-oxo-hexadecanoic acids; low-temperature HF treatments also reveal sugar units that are covalently attached to the hydroxyfatty acids. Parallel investigations of solvent-swollen cutin using 2D NMR spectroscopy assisted by magic-angle spinning yield well-resolved spectra that permit detailed comparisons to be made among chemical moieties present in the intact biopolymer, the soluble degradation products, and the unreacted solid residue.

Citrus↗

PubMed2001

A pair of 24-hydroperoxyl epimeric dammarane saponins from flower-buds of Panax ginseng.

Further investigation on the saponins of the flower-buds of Panax ginseng C. A. Meyer has resulted in the isolation and structural elucidation of a pair of new 24-epimers of dammarane type saponins named ginsenoside I and II. The structures of the epimers were characterized on the basis of chemical and spectral evidence as 3-O-[beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl]-20-S-O-beta-D-glucopyranosyl-3beta, 12beta,20(S)-trihydroxy-24xi-hydroperoxydammar-25-ene, except for their C-24 configurations. Ginsenoside I is a new triterpene glycoside, and ginsenoside II is a known compound first isolated from a natural plant.

Chromatography, High Pressure Liquid↗

PubMed2001

[Correlation of c-myc gene amplification, MTS1/p16 gene alternation, and HBV infection in human hepatocellular carcinoma].

OBJECTIVE: To observe the roles of c-myc gene amplification, MTS1/p16 gene alternation, and HBV infection in the pathogenesis and progression of hepatocellular carcinoma (HCC). METHODS: A d-PCR-PAGE-laser scanning technique was used to define amplifications of c-myc oncogene. Alternations of MTS1/p16 gene exon1 and exon2 were analysed by PCR and single-strand conformation polymorphism (SSCP) silver stain method. HBV-DNA was assayed by PCR. RESULTS: (1)The positive rates of c-myc gene amplification of HCCs and their paired non-cancerous liver tissues were 44.83% (13/29) and 51.72% (15/29). The discrepancies between them were not significant (P>0.05), but they were both significantly higher than that of cirrhotic liver tissues (8.33%, 1/12, P<0.05). (2)A total of 3 homozygous deletions and no mutations of MTS1/p16 gene exon1 and exon2 in HCCs were found in the subset of HCCs. (3)The discrepancies of the positive rates of HBV-DNA among normal liver (14.29%, 2/14), cirrhotic liver (66.67%, 8/12) and HCCs (96.55%, 28/29) were significant (P<0.001). Moreover, the HBV-DNA positive rates increased according to the development of liver lesions (b=0.3986, P<0.001). CONCLUSIONS: (1)C-myc gene amplification and HBV infection are closely related to the development and progression in a subset of HCCs. However, c-myc gene amplification does not correlate with the HBV infection in HCCs. (2)The homozygous deletions and mutations of MTS1/p16 gene are infrequently encountered in the subset of HCCs.

Carcinoma, Hepatocellular↗

PubMed2001

[Cytomeglovirus infection after liver transplantation].

OBJECTIVE: To study the prophylaxis, diagnosis and treatment of cytomegalovirus (CMV) infection after liver transplantation. METHODS: The clinical data of 10 patients receiving liver transplantation from July 1999 to October 2000 in our hospital were retrospectively analyzed along with literature review. RESULTS: CMV infection occurred asymptomatic cally in 6 patients, of whom, 5 were cured. CONCLUSIONS: Fluorogenic quantitative PCR (FQ-PCR) is effective, sensitive and highly specific for detecting CMV infection. It is important to monitor the status of CMV infection in patients receiving liver transplantation preoperatively and postoperatively. The key point for prophylaxis and treatment of CMV infection is early prevention and treatment after operation. Ganciclovir can exert significant therapeutic effects on CMV infection.

Adult↗

PubMed2000

Dimethyl azo(bisisobutyrate) and C(60) produce 1,4- and 1, 16-Di(2-carbomethoxy-2-propyl)-1,x-dihydro

Thermal decomposition of dimethyl azo(bisisobutyrate) in a solution containing C(60) produced 1,4- and 1, 16-di(2-carbomethoxy-2-propyl)-1,x-dihydro[60]fullerenes in yields of 21% and 27%, respectively, based on reacted C(60). The structure of this first 1,16-dialkyl-1,16-dihydro[60]fullerene was assigned from (13)C 2D INADEQUATE NMR spectra. The 1,16-isomer has first and second electrochemical reduction potentials shifted positively by 0. 18 V relative to those of the 1,4-isomer. From the close similarity of all spectral, chromatographic, and electrochemical data, the previously unassigned isomer of 1,x-di(2-cyano-2-propyl)-1, x-dihydro[60]fullerene, which was obtained from azo(bisisobutyronitrile) and C(60), is also a 1,16-isomer.

Journal Article↗

PubMed2000

Forming supramolecular networks from nanoscale rods in binary, phase-separating mixtures

Simulations show that when low-volume fractions of nanoscale rods are immersed in a binary, phase-separating blend, the rods self-assemble into needle-like, percolating networks. The interconnected network arises through the dynamic interplay of phase-separation between the fluids, through preferential adsorption of the minority component onto the mobile rods, and through rod-rod repulsion. Such cooperative effects provide a means of manipulating the motion of nanoscopic objects and directing their association into supramolecular structures. Increasing the rod concentration beyond the effective percolation threshold drives the system to self-assemble into a lamellar morphology, with layers of wetted rods alternating with layers of the majority-component fluid. This approach can potentially yield organic/inorganic composites that are ordered on nanometer scales and exhibit electrical or structural integrity.

Journal Article↗

PubMed2000

Laser activation voltammetry: selective removal of reduced forms of methyl viologen deposited on glassy carbon and boron-doped diamond electrodes

The effect of high-intensity laser pulses on the reduction of methyl viologen at glassy carbon electrodes in aqueous solution is investigated using laser activation voltammetry (LAV) under both channel flow and no-flow conditions and compared with the effect of conventional variable-temperature voltammetry. The reduction proceeds in two consecutive one-electron steps, and the neutral two-electron-reduction product of methyl viologen is shown by voltammetry and in situ optical microscopy to form two types of deposits, amorphous and crystalline, on the electrode surface. Laser activation voltammetry using a 10 Hz pulsed Nd-YAG 532 nm laser is shown to remove the deposits from the electrode surface at different laser intensities: the amorphous material is more easily ablated than the crystalline deposit. By conventional variable-temperature voltammetry, it is shown that the two stripping peaks disappear as the temperature is increased. However, with conventional heating, the opposite ease of removal is detected compared to the case of laser activation voltammetry: the stripping response associated with the crystalline material disappears at lower temperatures compared to that for the amorphous material. In the presence of high-intensity laser pulses (>0.17 W cm(-2)), glassy carbon surfaces are damaged and the voltammetric characteristics become poor. It is shown that, by the employment of a thin-film boron-doped diamond electrode grown using a chemical vapor deposition procedure on a tungsten substrate, much higher laser intensities can be applied and well-defined LAV signals can be obtained without deactivation of the electrode.

Journal Article↗

PubMed2000

Three new flavonol galloylglycosides from leaves of Acacia confusa.

Myricetin 3-O-(2"-O-galloyl)-alpha-rhamnopyranoside 7-methyl ether (1), myricetin 3-O-(3"-galloyl)-alpha-rhamnopyranoside 7-methyl ether (2), and myricetin 3-O-(2",3" -di-O-galloyl)-alpha-rhamnopyranoside (3), three new flavonol galloylglycosides, were isolated from leaves of Acacia confusa sampled from Chaoushi in the north of Taiwan. Their structures were established by analysis of spectroscopic data, and the compounds were evaluated for anti-hatch activity against brine shrimp.

Acacia↗

PubMed2000

Hepatectomy for huge primary liver cancer: report of 171 patients.

OBJECTIVE: To discuss the safety and feasibility of hepatectomy for huge primary liver cancer (PLC). METHODS: The effect of resection of huge PLC was examined retrospectively. Some problems about resection of huge PLC were discussed. RESULTS: In 171 patients with huge PLC undergoing hepatectomy, 2 (1.2%) died in one month after operation. The 1-, 2-, 3-, 5- and 10-year survival rates of the patients were 66.1%, 42.1%, 32.7%, 12.2% and 2.3%, respectively. The effect of prolonging survival time was significant. CONCLUSION: Hepatectomy for huge PLC is safe, feasible, and effective.

Adolescent↗

PubMed2000

[Pericardial devascularization with splenectomy for the treatment of portal hypertension].

OBJECTIVE: To review our experiences in and evaluate the efficacy of pericardial devascularization with splenectomy for the treatment of portal hypertension. METHODS: From May 1972 to October 1999, 508 patients with portal hypertension were treated with this operation. 319 of them had posthepatitic cirrhosis, and 141 late stage schistosomiasis or accompanied chronic viral hepatitis. RESULTS: The bleeding control rate was 94.1%, and the overall operative mortality rate was 4.5%. The major causes of death were upper gastrointestinal bleeding, intraabdominal hemorrhage, hepatic failure and hepatorenal syndrome. The mean follow-up time was 3.8 years. The 5-year survival rate was 94.1%, and the 10-year survival 70.7%. The 5-year recurrent bleeding rate was 6.2%. The 10-year recurrent bleeding rate was 13.3%. The rate of postoperative hepatic encephalopathy was 2.5% at 5 years, and 4.1% at 10 years. CONCLUSIONS: Pericardial devascularization with splenectomy was the first choice for the treatment of portal hypertension, especially for posthepatitic cirrhosis. The following were our experience: (1) thorough porto-azygos disconnection; (2) performing the operation in according to pericardial anatomy with correct surgical techniques; (3) selection of operative candidates and opportunity; (4) emphasizing perioperative management and preventing complications.

Adolescent↗

PubMed2000

[Prognostic factors of clinical curative effect for malignant obstructive jaundice].

OBJECTIVE: To explore prognostic factors for clinical treatment of patients with malignant obstructive jaundice. METHODS: 17 variables from 216 consecutive patients with malignant obstructive jaundice admitted from 1990 to 1997 were included for statistical analysis. RESULTS: The overall mortality was 19.9% (43/216), and the morbidity 37.5% (81/216). The morbidity of radical operation was higher than that of palliative operation (P < 0.01). There was a highly significant correlation between mortality, morbidity, ASA grade and duration of jaundice (P < 0.01). No correlation was seen between the mortality, type of operation and cause of jaundice. There was a highly significant correlation between the morbidity and the type of operation. CONCLUSIONS: The choice of operation in patients with malignant obstructive jaundice is radical operation. Early diagnosis and choice of treatment are essential to improving carative effect.

Adult↗

PubMed2000

[Seven years' summary report on the treatment of acute promyelocytic leukemia with arsenic trioxide--an analysis of 242 cases].

OBJECTIVE: To observe the effectiveness of arsenic trioxide (As(2)O(3)) in the treatment of acute promyelocytic leukemia (APL). METHODS: Data of clinical observation, seven year follow-up survey were analysed with American SAS system software, concentration of arsenic in cerebrospinal fluid (CSF) was determined by atomic absorbing spectrum. RESULTS: The complete remission (CR) and effectiveness rates were 87.9% and 94.4% for the previously untreated group; 60.0% and 65.0% for the relapsed in As(2)O(3) maintenance treatment group; 69.5% and 84.8% for the relapsed in other than As(2)O(3) maintenance treatment group; and 48.7% and 94.1% for the refractory group, respectively. In the previously untreated group, the relapse rate at 3 years after CR was 26.7%. The probability of survival in 136 follow-up survey patients was 92.0% and 76.7% at 5 years and 7 years, respectively. There were mild side effects. Central nervous system leukemia (CNSL) occurred in 138 out of 412 cases in 6 years, including some refractory leukemia, extramedullary residual leukemia and extramedullary relapse. Prophylactic intrathecal injection could reduce the incidence rate of CNSL. Determination of arsenic concentration indicated that it was difficult for arsenic to penetrate the blood-brain barrier. CONCLUSION: The CR rate and long-term survival are high and the relapse rate is low in APL patients treated with As(2)O(3). There is no cross-resistance between ATRA and As(2)O(3) and other chemotherapeutic agents. As(2)O(3)-resistance occurs scarcely. It can also be used in maintenance treatment.

Adolescent↗

PubMed2000

[Determination of three principal components in chuanjing tablets by using high performance liquid chromatography].

Uniform design method was employed to optimize the mobile phase of HPLC in order to determine simultaneously three principal components, theophylline, amobarbital and methylephedrine hydrochloride, in Chuanjing tablet, a compound preparation for asthma and cough. The stationary phase was ODS and the optimal mobile phase composition was V (0.015 mol/L phosphate buffer containing 0.3% triethylamine, pH 4.9): V (methanol) = 35:65. The detection was performed at 215 nm and the sensitivity was time programmed for simultaneous determination of minor and major components. Caffeine was selected as the internal standard. A baseline separation was achieved within 10 min. The linear ranges for theophylline, amobarbital and methylephedrine hydrochloride were 0.03 g/L-0.20 g/L, 7.5 mg/L-50.0 mg/L and 7.5 mg/L-50.0 mg/L, recoveries 99.7%-102.6%, 98.5%-100.2% and 98.0%-102.7%, inter-day RSDs 0.23%-1.2%, 0.35%-2.5%, 0.33%-1.6% respectively. This HPLC method is rapid and accurate, and suitable for the quality control of the preparation.

Amobarbital↗

PubMed1999

Selective detection of ribose-methylated nucleotides in RNA by a mass spectrometry-based method.

Post-transcriptional methylation of ribose at position O-2' is one of the most common and conserved types of RNA modification. Details of the functional roles of these methylations are far from clear, although in tRNA they are involved at position 34 in regulation of codon recognition and in eukaryotic rRNAs they are required for subunit assembly. Experimental difficulties in the mapping of ribose methylations increase with RNA molecular size and the complexity of mixtures resulting from nuclease digestion. A new and relatively rapid approach based on tandem mass spectrometry is described in which any of four ion reaction pathways occurring in the mass spectrometer can be monitored which are highly specific for the presence of 2'-O -methylribose residues. These pathways emanate from further dissociation of ribose-methylated mononucleotide (Nmp) ions formed in the electrospray ionization region of the mass spectrometer to then form the base, methylribose phosphate or PO(3)(-)anions. The mass spectrometer can be set for detection of generic ribose methylation (Nm) in oligonucleotides, selectively for each of the common methylated nucleo-sides Cm, Gm, Am or Um or for specific cases in which the base or sugar is further modified. By direct combination of mass spectrometry with liquid chromatography the method can be applied to analysis of complex mixtures of oligonucleotides, as for instance from synthetic or in vitro reaction mixtures or from nuclease digests of RNA. An example is given in which the single ribose-methylated nucleoside in Escherichia coli 16S rRNA (1542 nt), N(4),O-2'-dimethylcytidine, is detected in 25 pmol of a RNase T1 digest and localized to the fragment 1402-CCCGp-1405 in a single 45 min analysis.

Escherichia coli↗